When upgrading the stock halogen / incandescent lamps to led lighting bulbs for Acura ILX bulbs, the Acura ILX bulb size guide will be much helpful, below are the bulb size guide for 2013 ~ 2017 Acura ILX; yet it is for reference only, it is suggested to check the owner manual to confirm the Acura ILX bulb size guide is correct before purchasing.
For 2013~2015 Acura ILX headlights High Beam headlamp: 9005 headlight bulbs ( DRL: Daytime running light ); Low Beam headlamp: H11 headlight bulbs for Acura ILX headlights with halogen capsule headlamp;
D2S headlights for Acura ILX headlights with HID headlamps.